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Datapro Reports onData Communications C23-659-101
Protocol Conversion Systems
In this report:
Netlink
SNA-Gate
Product Summary Analysis ...
-102 Editor's Note
Protocol conversion systems evolved
Characteristics ...
-106 to support communications between IBM (synchronous) and non-IBM
Pricing ...
-108 (asynchronous) environments. Proto- col converters allow the use ofless expensive, asynchronous peripheral devices for communications with an IBM host, and help integrate other- wise incompatible systems, thus pro- tecting a user's investment in hardware and software.
Description
Netlink's SNA-Gate allows conver- sion between systems employing async and IBM BSC protocols, and an IBM SNAlSDLC environment.
The unit emulates an IBM PU Type 2 cluster controller and accommo- dates up to 255 non-SNA devices.
Strengths
SNA-Gate is a versatile product that can function as a protocol converter, a cluster controller, a line concentra- tor, and a remote job entry station facility.
-By Martin Dintzis Assistant Editor
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Limitations
The unit supports only one IBM host via a 37X5 communications control- ler. Controllers marketed by IBM, Apertus Technologies, AT&T, and Memorex/Telex support multiple IBM and asynchronous hosts with- out the aid of a 37X5.
Competition
IBM, Apertus Technologies, AT&T, and Memorex/Telex.
Vendor Netlink, Inc.
3214 Sprint Forest Road Raleigh, NC 27604 (919) 878-8612 Prices
The asynclbisync 3703-1 ranges in price from $7,000 to $9,500; the 3703-1A, asynchronous-only model ranges from $4,000 to $8,000; and the 3703-lB, bisynchronous-only model costs between $5,250 and
$6,000. Netlink offers quantity dis- counts.
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Protocol Conversion Systems
Analysis
Product Strategy
The history of Netlink began nine years ago in Aus- tralia when a former employee of IBM, Paul Wood, established a company called Systems Tech- nology Pty, Ltd. In 1982, Wood introduced the company's first product, the 3703 Network Proces- sor. The product achieved so much success that European and American distributors (such as Co- dex) signed agreements to market 3703 technology.
(Codex sells and services SNA-Gate under the name 4255 SNA Gateway.) After the success of the first product, Wood established Netlink, Inc. in 1984 to expand the development of SNA technol- ogy in the United States. Netlink now manufac- tures SNA-Gate, the successor to the 3703 in Raleigh, NC. The company also markets SNA-Hub network concentrator, which is Netlink's alternative to a remote IBM 3720.
SNA-Gate is Netlink's answer to environ- ments in which bisynchronous and asynchronous devices exist within an SNA network. Although called a gate, the unit does not function as a gate- way between networks. Rather, SNA-Gate is actu- ally an IBM Physical Unit Type 2 (PU.T2) cluster
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Netlink's SNA~Gate allows asynchronous and bisynchronous devices to access Systems Net- work Architecture (SNA).
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N.tllnk SNA....Qat.
Datapro Reports on Data Communications
controller and a multifunction protocol converter in one device, connecting non-SNA devices to SNA networks. The specific equipment supported in- cludes bisync 3270 and
3780/2780devices, bisync hosts and minicomputers, and all asynchronous devices. The product has its own Intel 8086 micro- processor and memory, and functions as a
software-based system, accommodating a number of different protocols in the SNA network.
SNA-Gate connects to the host through an IBM 37X5 or compatible control unit running any version ofIBM's Network Control Program (NCP). Connection to the control unit occurs ei- ther directly or through a modem. Netlink's Net- work Support Program (NSP) provides downline load and upline dumping capabilities for network control information and status displays. Users can configure operating parameters through macros in NSP, which runs under MVS and DOS operating systems. SNA-Gate also supports IMS, CICS, TSO, and RJE (JES2, JES, and POWER), and op- erates under IBM's network management products.
SNA-Gate supports five basic software mod- ules for various types of emulation. The product supports a modular software structure that con- forms to that of SNA. The
Asynchronous Commu- nications Moduleallows ASCII devices to work as LU Type 0, Type 1, or Type 2 equipment in an SNA network. This module also supports access to RJE packages, and a "swap-on-bind" command allows a user to log on to a Type 2 device and then switch to a Type 1 device and reverse the process.
An
RJE Station Facilityallows SNA-Gate to act as a multiple logic unit (MLU) RJE station. A
Bisyn- chronous Communications Modulemaps BSC pro- tocols to SNA and allows IBM 2770, 2780, 3275, 3780,3741,3271,3174,3274,3275, and 3276 de- vices to access an SNA host. An optional
Bur- roughs Poll Select Moduleallows Burroughs TD 830 terminals to emulate LU Type 2 devices with TD 830 limitations, and TC 4000 printers to emu- late LU Type 1 units. This module also provides a Burroughs terminal-to-host upstream pass-through capability that allows the user to log on to either an IBM or Burroughs host.
Competitive Position
The need for communications across IBM's broad range of communications protocols, and conver- sion between IBM and non-IBM environments,
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Datapro Reports on Data Communications
Netlink SNLGate
Company Profile Netlink, Inc.
Corporate Headquarters
3214 Spring Forest Road Raleigh, NC 27604 (919) 878-8612 Officers
President and CEO: Steve McRae
Vice President, Strategic Planning: Paul Wood Director of Engineering:
Don Bouchard
Company Background Netlink, Inc. is a company dedicated to providing enhanced multivendor connectivity and systems management solutions for
SNA data communica- tions networks, thereby creating competitive ad- vantages for its custom- ers.
The company, originally known as Systems Tech- nology Pty, Ltd., was founded in 1979 by Paul Wood, who had previ- ously worked with IBM in the design and perfor- mance evaluation of SNA networks using advanced simulation techniques.
Like Wood, other Netlink executives possess ex- tensive career experience with IBM, in the develop- ment and marketing of
continues to drive a strong market for protocol converters. One trend in recent years, however, has been away from processors specializing in a single type of conversion (e.g., ASCIII ANSI display to IBM 3278 display) to intelligent communications controllers capable of transparently linking IBM BSC and SNA 3270, asynchronous host, token-ring LAN, and other environments concurrently. IBM, AT&T, Memorex/Telex, and Apertus Technologies (formerly known as Lee Data, which was renamed after being purchased by Intelligent Information Systems) currently offer IBM-compatible commu- nications controllers supporting this level of inte- gration.
IBM dominates the protocol conversion mar- ket with the 3174 Establishment Controller. Al- though IBM continues to market the 7171 Protocol Converter and the 3708 Network Conversion Unit, which accommodate a greater variety of devices through customizable tables, the vendor has clearly
@ 1990 McGraw· Hill. Incorporated. Reproduction Prohibited.
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SNA-related communica- tions products, and in the computer industry in gen- eral.
Initially, Systems Technol- ogy consulted on major SNA networking installa- tions. In 1982, Wood re- leased the firm's first product, the 3703 Net- work Processor. The suc- cess of this early protocol conversion product en- abled the company to build distribution and OEM relationships across the United States and in Europe. In 1984, Wood established Netlink, Inc.
through the backing of major venture capitalists, including Citicorp, Accel Partners, and Morgan Holland.
More recent hardware products released by the
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Protocol Conversion Systems
vendor include SNA- Gate, an advanced net- work interface that allows non-SNA devices to com- municate with SNA net- works, and SNA-Hub, which enables multiple SNA devices to communi- cate over shared, high- speed host trunks.
Netlink's SN/View main- frame software works with IBM's NetView to provide increased levels of network management in concentrated device environments.
Netlink has established itself as a leading interna- tional provider of SNA interconnections and transport facilities. The company has also signed strategic relationships with major computer and communications suppli- ers.
positioned the 3174 as its flagship protocol conver- sion product for the years to come.
Netlink's customers include end users who need gateway service to the SNA network, and manufacturers that want to incorporate their prod- ucts into the SNA market.
Netlink has earned a successful reputation abroad and is attaining a reputation domestically as a responsible company with reliable devices, but the struggle for dominance in the SNA environ- ment has become tougher since IBM has such a strong market presence in the U.S. End users with a mixed bag of protocols who have chosen SNA- Gate, however, are quick to recommend the de- vice.
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Decision Points
Netlink's SNA-Gate is a versatile product that can act as a protocol converter, a cluster controller, a line concentrator, and a remote job entry station facility. The unit provides multiple protocol con- versions, including concurrent asynchronous and bisynchronous to Systems Network Architecture (SNA). SNA-Gate emulates an IBM Physical Unit Type 2 cluster controller, providing a gateway to the IBM SNAlSDLC environment.
SNA-Gate supports direct, leased, multi- drop, and dial-up lines. The unit eliminates sepa- rate communications lines and host front-end ports for non-SNA devices.
Italso eliminates host/front- end processor support facilities, such as EP and NTO, for non-SNA devices. The product's capabil- ity for being softloaded and centrally managed
Figure 1.
SNA-Gate Operating as a PU.T2 Cluster Controller
IBM 319X IBM347X
Netlink SNA-Gate
Datapro Reports on Data Communications
makes it especially attractive. The softloading fea- ture of SNA-Gate allows a user to configure and reconfigure downstream resources without affect- ing VTAM and NCP.
SNA-Gate performs various applications, such as providing an SNA gateway for ASCII ter- minals. In this configuration, SNA-Gate connects to a 3705 communications controller and acts as a local concentrator in the network. Terminals can attach directly or via modems on dial-up or leased lines, and terminal users can access multiple appli- cation sessions at one time through hot-key switch- ing.
SNA-Gate also supports remote BSC-to-SNA protocol conversion. In this application, SNA- Gate attaches to the communications controller via a modem, and through a daisychain port, other SNA devices can share the line to the host. SNA- Gate can also function as a remote concentrator
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Opera~ing as. a pu. T2 cluster controller, SNA-Gate provides access to the IBM SNA environment for a variety of deVIces usmg asynchronous and IBM BSC protocols.
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Netlink SNA-Gate
in which up to 16'lines, including dial-up termi- nals, can attach to an SNA host. By using SNA- Gate to concentrate lines, users can conserve ports on a communications controller or front-end pro- cessor and eliminate the need to multiplex and de- multiplex datastreams at the local site. In addition, several SNA-Gates can be multidropped on the same line, allowing users to save a scanner or frame on the control unit.
SNA-Gate's software-based operation adapts to asynchronous protocols and a variety of BSC implementations, particularly older ones for which there are few conversion products. Many BSC de- vices operate differently from the IBM standard and, therefore, do not implement all functions. Be- cause SNA-Gate is software driven, it is possible to overcome idiosyncrasies in the BSC protocol that can affect operation in the SNA network.
Users ofBSC 3270 terminals attached to SNA-Gate can improve response times by upgrad- ing the line speed from the controller to SNA- Gate. In addition, customers with data collection applications on remote minicomputers that sup- port BSC 2780/3780 protocols can achieve signifi- cant reductions in the time required to transfer data into host computers.
Centrally controlled and loaded, SNA-Gate operates under IBM's network management pro- grams. Since the unit accommodates multiple pro- tocols downstream, users can achieve a pure SNA backbone in the network. A unique characteristic is its capability to allow a user to log on to an applica- tion through SNA-Gate as an LU Type 2 device, and switch to an LU Type 1 device. This feature allows interleaving operation in both interactive and batch modes.
SNA-Gate offers several advantages to the user in a typical IBM environment. Moving BSC processing to an SNA-Gate frees a significant number of 37X5 cycles for SNA processing, thereby making more efficient use of existing equipment. In applications in which incompatible terminals, such as an interactive 3270-type device and a remote RJE, perform input and high-speed output functions, SNA-Gate does not require in- compatible datastreams from these devices to share a band-splitting or channelized modem. By converting both streams to SNA, SNA-Gate elimi- nates the need for an Emulator Program and a byte-multiplex channel, and reduces the number of ports needed on the control unit.
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C23-659-10S
Protocol Conversion Systems
SNA_Gate also allows personal computers to dial into an SNA-Gate port and perform interac- tive and batch applications concurrently through a
"swap-on-bind" command that supports switching back and forth from LU Type 2 to LU Type 1 op- eration. By accommodating multiple logical units (MLUs) through a single port, SNA_Gate enables the personal computer to be in session with TSO while JES is transmitting output data to a printer or disk file. In this application, the personal com- puter user logs on to TSO, CICS, or IMS as a 3270 display screen, and then logs on to JES to emulate an IBM 3777/3/4 terminal with MLUs.
SNA-Gate's support for PC-to-host file transfer allows PC users to transfer files into host applications, such as TSO or CICS, through popu- lar PC-based file transfer programs. PC users can also transfer data directly into JES by emulating an RJE reader device.
By incorporating support for the Baudot Code into the product, Netlink has addressed the needs of customers who require only low-volume access to an SNA host. Without acquiring any more terminals, these users can now exchange mes- sages with an IBM host by using their telex ma- chines and inexpensive asynchronous modems.
SNA-Gate incorporates graphics support, allowing asynchronous terminals to access host- based graphics applications over a full-screen (LU.T2) session or a line-by-line LU.Tl session.
Netlink based the graphics support on the require- ments of the SAS/Graph program, but other graph- ics packages such as Tektronix Plot 10 can also use this feature. Devices supported include Tektronix 4010 terminals and 46XX plotters, HP 2600 dis- play terminals, or any PC executing the SAS/
R TERM terminal emulation program.
Two limitations of SNA-Gate are support for only one IBM SNA host connection, which must occur through an IBM 37X5 communications con- troller, and no access to asynchronous host envi- ronments. (Users, however, can still access multiple IBM hosts via 37X5 host attachment op- tions and functions provided by the IBM host- resident software.) Newer communications controllers on the market not only support conver- sion between async, BSC, and SNA protocols, but provide multiple, direct connections to IBM and asynchronous hosts, and accommodate token-ring networks. These newer products include IBM's
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Protocol Conversion Systems
3174 Establishment Controller, AT&T's 6544 Mul- tifunction Communication Controller, Memorex'
1174 Network Controller, and Apertus Technolo- gies' Datastar 5000 Communications System. The systems of AT&T, Memorex, and Apertus Technol- ogies also support enhanced functionality for at- tached display terminals, such as windowing on multiple sessions.
For async-to-SNA conversion, however, SNA- Gate still excels in the number and variety of devices that can be accommodated. The largest 3174 models, for example, can accept a maximum of only 64 synchronous and 24 ASCII displays con- currently, and the 3174 supports only 29 different display terminal models; if a user has a display ter- minal that is not on the 3174 list, that terminal cannot connect to the SNA environment. SNA- Gate, on the other hand, supports up to 255 non- SNA devices of any kind.
Through software assistance, IBM's 3708 Network Conversion Unit, another async-to-3270 protocol conversion product, can be expanded to include any asynchronous device. Unlike SNA-- Gate, however, the 3708 is limited to a maximum of 18 devices and cannot perform conversion of multiple protocols to SNA concurrently.
Characteristics
Models: 3703-1 (multifunction SNA-Gate); 3703-1 A (asynchronous-only version); and 3703-1 B
(bisynchronous-only model).
Date of First Announcement: 1986.
Date of First Delivery: 1986.
Number Installed to Date: Over 1,500.
Serviced by: Netlink, Inc.
NOVEMBER 1990
Netlink SNA-Gate
Models
Datapro Reports on Data Communications
SNA_Gate is a cluster controller that can connect up to 255 non-SNA devices to SNA networks. Bisynchronous and asynchronous terminals can connect directly to SNA-Gate, or indirectly through modems. The unit pro- vides a 3270 emulator that acts like a 3274 51 C control unit to which 3278 display stations can be attached.
Netlink offers the product in three versions:
• 3703-1: Multifunction SNA-Gate supports concur- rent async/BSC conversion to and from SNA
• 3703-1A: Asynchronous SNA-Gate converts async devices to SNA
• 3703-1 B: Bisynchronous SNA-Gate interfaces bi- sync 3270, 3780/2780, and other bisync devices to SNA
Configuration
The basic SNA-Gate consists of the following:
• An Intel 8086, 16-bit microprocessor running at 8M Hz with 128K bytes of ROM for diagnostics and loading from the host, as well as 1 M byte of RAM, some of which is reserved for the down line-loaded programs and data buffers
• One SDLC daisychain communications port using Direct Memory Access (DMA)
• Asynchronous or synchronous communications port cards for a maximum of 16 ports
• An industry-standard Multibus backplane for the in- sertion of additional circuit cards
Users can configure SNA-Gate to extend network man- agement and SNA session integrity down to the BSC device level. SNA-Gate can supply a secure mapping of SNA services into a BSC subnetwork.
The RJE Station Facility enables inexpensive asynchronous or BSC terminals to appear as RJE work- station devices to an IBM JES host, capable of inputing card-image data or receiving print data at a remote loca- tion. In this environment, SNA-Gate appears to the host as an IBM 3770 single or multiple logical unit remote RJE workstation. SNA-Gate incorporates session initia- tion and session recovery features and provides flexibil- ity in selecting attached devices to receive JES
datastreams.
Configuration options enable SNA-Gate to recog- nize that file transfer is occurring and to change its mode of operation to support maximum data through- put. Among some ofthe programs supported are IBM's PC/HOST File Transfer and Terminal Emulator Program (FTTERM), Coefficient Systems' VTERM II, and RELAY Communications' Relay Gold. SNA-Gate also supports PC file transfer directly into the IBM JES programs.
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Metlink SMA-Gate
Transmission Specifications
SNA_Gate houses all the hardware required to support up to 16 ASCII and/or bisync lines in any combination.
The device acts as a multifunction IBM Physical Unit Type 2 (PU.T2) cluster controller that concurrently maps multiple protocols from attached devices to IBM Logical Unit (LU) 0, 1, and 2. SNA-Gate supports the following conversions: ASCII to SNA; BSC 3271 and 3275 to SNA;
and RJE to SNA. The unit connects to an SNA host di- rectly or remotely via a modem through an IBM 37X5 or compatible communications controller running any ver- sion of IBM's Network Control Program (NCP). A host- resident VT AM application, called the Network Support Program (NSP), sends SNA-Gate its operating configu- ration and receives memory dumps and diagnostics.
SNA-Gate does not support a direct channel attach- ment to the host, but it can interface with the host through an Integrated Control Adapter (ICA), an Inte- grated Communications Processor (ICP), or a 37XX Communications Controller.
SNA-Gate allows an asynchronous printer to par- ticipate in an IBM Logical Unit Type 3 with a host appli- cation. IBM's Logical Unit Type 3 enables intelligent printers to interpret and execute 3270 buffer commands and orders, typically sent on an LU T2 session. In this environment, SNA-Gate performs command interpreta- tion and data management for the printer.
The Network Support Program (NSP) also fur- nishes downline loading and upline dumping capabilities for network control information and status displays.
Macros in NSP provide the means to configure SNA_
Gate ports for ASCII or BSC operation. NSP works un- der the MVS and DOS operating systems. SNA-Gate interfaces with IBM host database subsystems, includ- ing IMS, CICS, TSO, and RJE (JES2, JES3, and POWER). In addition, SNA_Gate responds to com- mands from IBM's network management products.
SNA-Gate supports a 64K bps, SOLC data link on the host side and 300 to 9600 bps links to data devices on the terminal side. The unit connects to the host through multidrop, dial-up, or leased lines. Through an integral modem-sharing facility, SNA-Gate can be dai- sychained so that other SNA devices can share the same line. In this type of application, SNA-Gate ap- pears as a multidropped PU.T2 in the network.
SNA-Gate's SOLC port, which serves as the link to the host, supports the following: an RS-232-C con- nector; internal or external clocking; synchronous or asynchronous transmission; 110 to 19.2K bps transmis- sion speeds; half- or full-duplex operation; and NRZI or non-NRZI coding. An optional V.35 interface card sup- ports SOLC speeds to 64K bps. Users can configure the SOLC port for any eight-bit SOLC polling address.
A digital splitter on the SOLC port drives the dai- sychain port, which appears as a multidrop on the SOLC link. This port has an RS-232-C interface and can take or supply clocking. It has pass-through signals on pins 2 through 8,15,17,20, and 24.
Devices attach to the SNA-Gate through terminal ports that support the RS-232-C interface, internal or
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Protocol Conversion Systems
external clocking, full EIA pinout, OTE or OCE operation, synchronous or asynchronous transmission, full-duplex operation, and 300 to 9600 bps transmission speeds.
SNA-Gate supports the five-bit CCITT alphabet No.2, also known as the Baudot Code, which enables telex machines to communicate over an SNA network through an LU.T1 session.
Device Control
The installation of SNA-Gate resembles the installation of any other SNA-type controller. SNA-Gate must be accurately identified to VTAM, NCP, and host sub- systems, and all devices attached to SNA-Gate must be defined through configuration macros. To generate an SNA-Gate configuration, users must assemble mac- ros defining the characteristics of each SNA-Gate at- tachment and execute a configuration generator program to format internal tables for devices attached to the SNA-Gate. The system incorporates supermac- ros that define the characteristics of commonly used terminals. Error indications show up on an alphanu- meric display, and LEOs monitor system status and line activity. ASCII and BSC port parameters, configured via a host-resident Network Support Program, are downline loaded to SNA-Gate.
If necessary, a user can extend supermacros and retain configurations and executable code in a host- resident library. ASCII and BSC port parameters, con- figured via the host-resident Network Support Program, are downloaded to SNA-Gate. (The NSP controls SNA- Gate when it is attached to the network.)
SNA_Gate's operating program includes com- mands used to communicate with the host and the NSP that resides within it. These commands send a message from the SNA-Gate to the host, establish a local ses- sion between SNA-Gate and another attached device, establish a session with SNA-Gate's Network Proces- sor Control Point, display SNA-Gate status, send an SNA command, send a message on behalf of another attached device, or end a local session. A user can en- ter the SNA-Gate commands from any attached device that supports a keyboard.
After power-on or reset, SNA-Gate runs a series of diagnostics for ROM checksum, RAM nondestructive and destructive tests, an SOLC line test, a timer test, and a test of power supplies. After successful comple- tion of the diagnostic tests, a bootstrap program logs on to the host-resident NSP and identifies itself by sending a logon from the Network Processor Control Point, which provides network services such as loading, dumping, and status. Logon requests repeat automati- cally every two minutes until a session is bound with NSP. When a session is bound, the SNA-Gate either dumps or loads its memory. After the operating pro- gram, configuration, and any patches are loaded into SNA-Gate, NSP is unbound. No further communication occurs between SNA-Gate and NSP until another downline load or upline dump is required or an operator
NOVEMBER 1990
C23-659-1oa Protocol Conversion Systems
sends a command through NSP to the SNA-Gate Net- work Processor Control Point.
Users can monitor and control the activity of NSP through a Network Support Console, which can be any configuration-authorized LU Type 1, Type 2, or Type 3 device located anywhere in the network. While logged on, the console receives messages about NSP activi- ties. To access these messages, users enter a pre- defined terminal logon sequence and a valid password.
After logon through a Network Support Console, an op- erator can command a printer to log all NSP message traffic. Through a series of NSP commands entered through the console, operators can perform a variety of functions, such as starting or stopping a log of NSP ac- tivity, adding an SNA-Gate definition to those defined in the start-up procedure, reloading the SNA-Gate from the host, and communicating with the Network Proces- sor Control Point about SNA-Gate control.
To implement emulation, SNA-Gate supports software modules, which include SNA PU.T2, Asynchro- nous Communications, RJE Station Facility, and Bisyn- chronous Communications. The modules provide the following basic functions:
o SNA PU.T2-provides a modular software structure with well-defined interfaces between layers that con- form to the structure of SNA. Discrete layered sup- port includes Data Link Control, Path Control, Transmission Control, Data Flow Control, Network Addressable Unit Services, up to 255 Logical Units, SNA Capabilities, and Communications Network Management.
o Asynchronous Communications-allows asynchro- nous ASCII devices (TTY compatible) to work as LU Type 0, Type 1, or Type 2 devices in an SNA net- work. Additional support enables an ASCII device to look like the datastream from an IBM 3767 or 3776 with an extension supporting outbound Function Management Headers. This feature allows access to RJE packages, TSO, CICS, and IMS. ASCII devices that operate with SNA-Gate include keyboard print- ers, terminals, visual display units (VDUs), microcom- puters, minicomputers, output-only devices, letter- quality printers, plotters, and optical character readers. The asynchronous module supports IBM 3767 screens in line-by-line or full-screen emulation of IBM 3278 Models 2, 3, 4, and 5 and 3279 four- color devices. This feature allows asynchronous ASCII VDUs to be functionally compatible with IBM 3278 VDUs. The module provides code and configu- ration parameters that take advantage of functions similar to those of an IBM 3278, commonly available on ASCII screens. An ASCII module "swap-on-bind"
command allows a user to log on to SNA-Gate as an
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Datapro Reports on Data Communications
LU Type 2 device and then switch to an LU Type 1 deviCe and reverse the process. Another command
au~horiz~s tht! placement of multiple logical units on , i! sin~le ASCII port.
o RJE Station FaCility-allows SNA-Gate to act as a multiple logical unit (MLU) RJE station. The RJE Sta- tion Facility consists of a series of up to eight LUs that can log on to JES2 or J ES3 automatically when SNA-Gate is loaded or from any device attached to SNA-Gate. To achieve this capability, the user must define additional LUs (end of sessions that run on the logicalline~defined in JES2 rather than on physi- cal devices in SNA-Gate). LU Type 1 devices that establish local sessions with the RJE Station Facility identify themselves as readers, printers, punches, exchange disks, or consoles.
o Bisynchronous Communications-maps BSC proto- cols to SNA. This capability allows IBM 2770, 2780, 3780, and 3741; polled 3780 or 3270 devices; as well as RJE and data-entry terminals, minicomputers, mi- crocomputers, or mainframes using the BSC proto- col, to access a host operating under SNA. The mapping performed for BSC preserves the end-to- end nature of SNA.
As an option, users can equip SNA-Gate with a Bur- roughs Poll Select Emulator module so that Burroughs TD 830 terminals can emulate LU Type 2 devices with limitations and TC 4000 printers can emulate LU Type 1 units. This module also offers the following capabilities:
upstream pass-through for Burroughs terminals to a Burroughs 6700, 6800 CPU; the ability to log on to ei- ther an IBM or Burroughs host and switch between the two on a session basis; support, through configuration macros, for configuring Burroughs terminals; and LU Type 0 emulation.
Physical Specifications
SNA-Gate is 7.08 inches high, 17.44 inches wide, 19.125 inches deep, and weighs approximately 30 pounds. Power requirements are as follows: 120 V AC or 240 V AC; 140 W; and 50 to 60 Hz.
Pricing,
The async/bisync 3703-1 ranges in price from $7,000 to
$9,500; t!le 3703-1 A, asynchronous-only model ranges from $4,000 to $8,000; and the 3703-1 B,
bisynchronous-only model costs between $5,250 and
$6,000. Netlink offers quantity discounts . •
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Netlink SNA-Gate
datapro
ANALYSIS
UPDATE: Since our last report on this product, Netlink has made significant enhancements to it, adding the fol- lowing: multiple LU T2 session support for asynchronous terminals; support for graphics terminals; support for PC- to-host file transfer; performance improvements for BSC and asynchronous devices; new 64K bps SDLC connection to a central site host; enhancements to the RJE station facility; LU T3 support for asynchronous printers; en-
hancements to BSC support; and support for Baudot Code.
The history of Netlink began nine years ago in Australia when a former employee of IBM, Paul Wood, established a company called Systems Technology Pty, Ltd. In 1982, Wood introduced the company's first product, the 3703 Network Processor. The product achieved so much suc- cess that European and American distributors (such as Codex) signed agreements to market 3703 technology.
(Codex sells and services SNA-Gate under the name 4255 SNA Gateway.) After the success of the first product, Wood established Netlink, Inc. in 1984 to expand the development of SNA technology in the United States.
Netlink now manufactures SNA-Gate in Raleigh, North Carolina. The company also markets SNA-Hub network concentrator, which is Netlink's alternative to a remote IBM 3720.
SNA-Gate is Netlink's answer to environments in which bisynchronous and asynchronous devices exist within an SNA network. Although called a gate, the unit does not function as a gateway between networks. Rather, SNA- _Gate is actually an IBM Physical Unit Type 2 (PU.T2)
VENDOR: Netlink Inc., 3214 Spring Forest Road, Raleigh. North Carolina 27604. Telephone (919) 878-8612. (800) NETLINK.
MODELS: 3703-1 (multifunction SNA_Gate);
3703-1 A (asynchronous-only version); and 3703- 1 B (bisynchronous-only model).
COMPETITION: IBM 3708. 3710. and 3274 51 C control unit.
PRICE: 3703-1 ranges from $6,000 to $9,500;
3703-1 A ranges from $4,000 to $8.000; and 3703-1 B ranges from $4.500 to $6,000. Netlink offers quantity discounts.
REPORT HIGHLIGHTS: PAGE
Market Position ... 104 SPECIFICATIONS ... 104 PRICING ... 107
cluster controller and multifunction protocol converter in one device, connecting non-SNA devices to SNA net- works. The specific equipment supported includes bisync 3270 and 3780/2780 devices, bisync hosts and minicom- puters, and all asynchronous devices. The product has its own Intel 8086 microprocessor and memory and func- tions as a software-based system, accommodating a num- ber of different protocols in the SNA network.
PRODUcr EVALUATION
Netlink's SNA-Gate is a versatile product that can act as a protocol converter, a cluster controller, a line concentra- tor, and a remote job entry station facility. The unit pro- vides multiple protocol conversions, including concurrent
Netlink's SNA_Gate allows asyn- chronous and bisynchronous de- vices to access Systems Network Architecture (SNA).
MAY 1989 COPYRIGHT © 1989 McGRAW-HILL, INCORPORATED. REPRODUCTION PROHIBITED DA T APRO RESEARCH. DELRAN NJ 08075 USA
C23-659-102 Protocol Conversion Systems
Netlink SNtLGate
asynchronous and bisynchronous to Systems Network Ar- chitecture (SNA). The SNA-Gate emulates an IBM Phys- ical Unit Type 2 cluster controller, providing a gateway to the IBM SNA/SDLC environment.
SNA_Gate is basically an upgraded version of Netlink's 3703 Network Processor. The 3703 had 12 ports, but SNA_Gate supports 16 non-SNA lines over an SNAI SDLC host link. The 3703 handled 9600 bps upstream, but SNA-Gate can handle up to 64K bps. Netlink has greatly expanded the memory of the product to either 512K or 704K bytes, whereas the 3703 Network Processor had a 384K-byte memory capacity. The 3703 also came in two models only: one supporting both bisynchronous- and asynchronous-to-SNA conversions and the other support- ing asynchronous-to-SNA conversions only. Netlink has taken SNA-Gate one step further by creating a third ver- sion that supports bisynchronous-only conversion.
Netlink has also made the price of SNA-Gate more at- tractive than its predecessor's. The 3703 async/bisync ver- sion began at $8,700 for four ports, while the newer model costs $2,700 less. .
SNA-Gate supports direct, leased, multidrop, and dial-up lines. The unit eliminates separate communications lines and host front-end ports for non-SNA devices. It also eliminates host/front-end processor support facilities such as EP and NTO for non-SNA devices. The product's capa- bility for being softloaded and centrally managed makes it especially attractive. The softloading feature of SNA- _Gate allows a user to configure and reconfigure down- stream resources without affecting VTAM and NCP.
SNA-Gate differs from many other protocol converters on the market in its capability for handling a number of protocols at once. Many conversion products handle only one type of protocol conversion, such as ASCII to SDLC, at one time. Users who need mOre than one type of con- version in a network must purchase separate units for each type desired. SNA-Gate offers all of the following conversions in one product: asynchronous (ASCII) to SNA; BSC 3271 and 3275 to SNA; and RJE to SNA.
SNA-Gate is a versatile product that performs various applications, such as providing an SNA gateway for ASCII terminals. In this configuration, SNA-Gate connects to a 3705 communications controller and acts as a local con- centrator in the network. Terminals can attach directly or via modems on dial-up or leased lines. As a recent en- hancement, Netlink has expanded asynchronous ASCII support by enabling a terminal user to sustain multiple application sessions at one time and using hot-key switch- ing between sessions.
SNA-Gate also supports remote BSC-to-SNA protocol conversion. In this application, SNA_Gate attaches to the communications controller via a modem, and through a daisychain port, other SNA devices can share the line to the host. SNA-Gate can also function as a remote concen-
trator in which up to 16 lines, including dial-up terminals, can attach to an SNA host. By using SNA_Gate to con- centrate lines, users can conserve ports on a communica- tions controller or front-end processor and eliminate the need to multiplex and demultiplex datastreams at the local site. In addition, several SNA-Gates can be multi- dropped on the same line, creating the possibility of users' saving a scanner or frame on the control unit.
SNA-Gate connects to the host through an IBM 37X5 or compatible control unit running any version of IBM's Network Control Program (NCP). Connection to the con- trol unit occurs either directly or through a modem.
Netlink's Network Support Program (NSP) provides downline load and upline dumping capabilities for net- work control information and status displays. Users can configure operating parameters through macros in NSP, which runs under MVS and DOS operating systems. SNA- _Gate also supports IMS, CICS, TSO, and RJE (JES2, JES, and POWER) and operates under IBM's network management products.
SNA-Gate supports five basic software modules for vari- ous types of emulation. The product supports a modular software structure that conforms to that of SNA. The asynchronous communications module allows ASCII de- vices to work as LU Type 0, Type 1, or Type 2 equipment in an SNA network. This module also supports access to RJE packages, and a "swap-on-bind" command allows a user to log on to a Type 2 device and then switch to a Type 1 device and reverse the process. An RJE Station Facility allows SNA-Gate to act as a multiple logic unit (MLU) RJE station. A bisynchronous communications module maps BSC protocols to SNA and allows IBM 2770,2780,3275, 3780, 3741,3271, 3274, 3275, and 3276 devices to access an SNA host. An optional Burroughs Poll Select module allows Burroughs TD 830 terminals to emulate LU Type 2 devices with TD 830 limitations and TC 4000 printers to emulate LU Type 1 units. This mod- ule also provides a Burroughs terminal-to-host upstream passthrough capability that allows the user to log on to either an IBM or Burroughs host.
SNA_Gate's Software-based operation adapts to asyn- chronous protocols and a variety of BSC implementa- tions, particularly older ones for which there are few conversion products. Many BSC devices operate differ- ently from the IBM standard and, therefore, do not imple- ment all functions. Because SNA-Gate is software driven, it is possible to overcome idiosyncrasies in the BSC proto- col that can affect operation in the SNA network.
This most recent release of SNA-Gate supports twice the number of BSC lines than the previous release and also doubles line speeds. According to Netlink, new program- ming techniques have effected this change. When SNA- _Gate connects to the host via a 9600 bps, half-duplex SDLC line, connectivity capabilities support the follow- ing: two 9600 bps, half-duplex downstream BSC lines, or
COPYRIGHT © 1989 McGRAW-HILL, INCORPORATED. REPRODUCTION PROHIBITED DATAPRO RESEARCH, DELRAN NJ 08075 USA
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C23-659-103 Protocol Conversion Systems
Netlink SNA-Gate
3277 3279
t SSC t
IBM HOST
ASCII t t ASCII/BSC RJEt
Figure 1. SNLGate operating as a PU.T2 cluster controller provides a gateway to the IBM environment for a variety of devices using asynchronous ASCII and BSC protocols.
five 4800 bps, half-duplex downstream BSC lines, or twelve 2400 bps, half-duplex downstream BSC lines, or sixteen 1200 bps, half-duplex downstream BSC lines.
Users of BSC 3270 terminals attached to SNA_Gate can improve response times by upgrading the line speed from the controller to SNA-Gate. In addition, customers with data collection applications on remote minicomputers that support BSC 2780/3780 protocols can achieve signif- icant reductions in the time required to transfer data into host computers.
Centrally controlled and loaded, SNA-Gate operates un- der IBM's network management programs. Since the unit accommodates multiple protocols downstream, users can achieve a pure SNA backbone in the network. A unique characteristic is its capability to allow a user to log on to an application through SNA-Gate as an LU Type 2 de- vice and switch to an LU Type I device. This feature allows interleaving operation in both interactive and batch modes.
SNA-Gate offers several advantages to the user in a typi- cal IBM environment. Moving BSC processing to an SNA-Gate frees a significant number of 37X5 cycles for SNA processing, thereby making more efficient use of existing equipment. In applications in which incompatible terminals, such as an interactive 3270-type device and a remote RJE, perform input and high-speed output func- tions, SNA_Gate does not require incompatible datastreams from these devices to share a band-splitting or channelized modem. By converting both streams to SNA, SNA_Gate eliminates the need for an Emulator Program and a byte-multiplex channel and reduces the number of ports needed on the control unit.
SNA-Gate also allows personal computers to dial into an SNA-Gate port and perform interactive and batch appli- cations concurrently through a "swap-on-bind" command that supports switching back and forth from LU Type 2 to LU Type I operation. By accommodating MLUs through a single port, SNA-Gate enables the personal computer to be in session with TSO while JES is transmitting output data to a printer or disk file. In this application, the personal computer user logs on to TSO, CICS, or IMS as a
MAY 1989 COPYRIGHT © 1989 McGRAW-HILL, INCORPORATED. REPRODUCTION PROHIBITED DA T APRO RESEARCH, DELRAN NJ 08075 USA
C23-659-1 04 Protocol Conversion Systems
Netlink SNA-Gate
3270 display screen and then logs on to JES to emulate an IBM 3777/3/4 terminal with MLUs.
Recently, Netlink has enhanced support for PC-to-host file transfer by allowing PC users to transfer files into host applications such as TSO or CICS through popular PC- based file transfer programs. PC users can also transfer data directly into JES by emulating an RJE reader device.
Most protocol converters use an 8-bit, Z-80 microproces- sor, but SNA-Gate uses Intel's 8086, a 16-bit processor, for faster performance. On the asynchronous side, this increased processor power supports input froni sixteen PCs at 1200 bps in file transfer mode via an LUI flow or input from eight 2400 bps PCs transferring data in an LUI flow. On the bisynchronous side, the processor can accommodate two 9600 bps lines, four 4800 bps lines, or up to twelve lines at 2400 bps.
By incorporating support for the Baudot Code into the product, Netlink has addressed the needs of customers who require only low-volume access to an SNA host.
Without acquiring any more terminals, these users can now exchange messages with an IBM host by using their telex machines and inexpensive asynchronous modems.
Customers who select the V.35 interface card can multi- drop SNA gates with other SNA devices, such as an IBM 3174, to a single, high-speed data facility, thereby attain- ing greater price/performance from these links without investing in more equipment. In countries in which the telecommunications providers offer the 64K bps service over an X.21 interface, Netlink recommends that custom- ers install a V.35-to-X.21 interface converter module.
Netlink has incorporated graphics support into the latest version of its product. SNA-Gate allows asynchronous terminals to access host-based graphics applications over a full-screen (LU T2) session or a line-by-line LU T 1 ses- sion. Netlink based the- graphics support on the require- ments of the SAS/Graph program, but other graphics packages such as Tektronix Plot 10 can also use the new
SNA-Gate feature. Devices supported include Tektronix 4010 terminals and 46XX plotters, HP 2600 display ter- minals, or any PC executing the SAS/RTERM terminal emulation program.
MARKET POSITION
Netlink's customers include end users who need gateway service to the SNA network and manufacturers that want to incorporate their products into the SNA market. SNA- _Gate competes with the IBM 3710 in the area of bisync- to-SNA conversion. Both units support multiple downstream protocols including BSC RJE and asynchro- nous ASCII. However, SNA-Gate supports BSC 3275 devices, and the 3710 cannot.
In the area of async-to-SNA conversion, IBM's 3174 re- sembles SNA-Gate, but with one major difference: the 3174 supports about 21 different terminals. If a user has a terminal that is not on the 3174 list, that terminal cannot connect to the SNA environment. SNA_Gate supports all asynchronous devices.
Through software assistance, IBM's 3708, another com- petitor, can be expanded to include any asynchronous device but, like the 3174, this unit cannot effect concur- rent conversion of multiple protocols to SNA.
Unlike some other competitors, SNA-Gate supports re- mote softloading and EC/Release level changes over the SNA network, as well as a 3777 RJE facility with multiple LUs.
Netlink has earned a successful reputation abroad and is attaining a reputation domestically as a responsible com- pany with reliable devices, but the struggle for dominance in the SNA environment has become tougher since IBM has such a strong market presence in the U.S. End users with a mixed bag of protocols who have chosen SNA- _Gate, however, are quick to recommend the device.
SPECIFICA TIONS
MODELS: 3703-1 (multifunction SNA-Gate); 3703-1A (asynchronous-only version); and 3703-1 B (bisynchronous-only model).
DATE OF FIRST ANNOUNCEMENT: 1986.
DATE OF FIRST DELIVERY: 1986.
NUMBER INSTALLED TO DATE: Over 1,000.
SERVICED BY: Netlink, Inc.
MODELS
SNA-Gate is a cluster controller that can connect up to 255 non-SNA devices to SNA networks. Bisynchronous and asynchronous terminals can connect directly to SNA- _Gate or indirectly through modems. The unit provides a 3270 emulator that acts like a 3274 51C control unit to which 3278 display stations can be attached.
Netlink offers the product in three versions:
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Netlink SNA-Gate
• 3703-1: Multifunction SNA-Gate, supports concurrent async/BSC conversion to and from SNA
• 3703-1A: Asynchronous SNA-Gate, converts async de- vices to SNA
• 3703-1B: Bisynchronous SNA-Gate, interfaces bisync 3270, 3780/2780, and other bisync devices to SNA
CONFIGURA nON
The basic SNA-Gate consists of the following: an Intel 8086, 16-bit microprocessor running at 8MHz with 64K bytes of ROM for diagnostics and loading from the host, as well as 512K bytes of RAM, some of which is reserved for the downline-Ioaded programs and the rest for data buffers; one SDLC daisychain communications port using Direct Memory Access (DMA); and asynchronous or syn- chronous communications port cards for a maximum of
16 ports. The unit also incorporates an industry-standard Multibus backplane for the insertion of additional circuit cards.
Users can now configure SNA-Gate to extend network management and SNA session integrity down to the BSC device level. SNA_Gate can supply a secure mapping of SNA services into a BSC subnetwork.
The RJE Station Facility enables inexpensive asynchro- nous or BSC terminals to appear as RJE workstation de- vices to an IBM JES host, capable of inputing card-image data or receiving print data at a remote location. In this environment, SNA-Gate appears to the host as an IBM 3770 single or multiple logical unit remote RJE worksta- tion. Netlink has introduced new session initiation and session recovery features into Release 1.7 as well as added flexibility in selecting attached devices to receive JES datastreams.
Configuration options enable SNA_Gate to recognize that file transfer is occurring and to change its mode of opera- tion to support maximum data throughput. According to Netlink, a time reduction of 50 percent took place in a test involving the inbound transfer of 100,000 alphanumeric characters. Among some of the programs supported are IBM's PC/HOST File Transfer and Terminal Emulator Program (FTTERM), VTERM II from Coefficient Sys- tems, and Relay Gold from RELA Y Communications.
Netlink also announced support for PC file transfer di- rectly into the IBM JES programs.
TRANSMISSION SPECIFICATIONS
SNA-Gate houses all the hardware required to support up to 16 ASCII and/or bisync lines in any combination. The device acts as a multifunction IBM Physical Unit Type 2 (PU.T2) cluster controller that concurrently maps multi-
pIe protocols from attached devices to IBM Logical Unit (LU) 0, 1, and 2. SNA-Gate supports the following con- versions: ASCII to SNA; BSC 3271 and 3275 to SNA; and RJE to SNA. The unit connects to an SNA host directly or remotely via a modem through an IBM 37X5 or compat- ible communications controller running any version of IBM's Network Control Program (NCP). A host-resident VT AM application, called the Network Support Program (NSP), sends SNA-Gate its operating configuration and receives memory dumps and diagnostics. SNA_Gate does not support a direct channel attachment to the host, but it can interface with the host through an Integrated Control Adapter (lCA), an Integrated Communications Processor (ICP), or a 37XX Communications Controller.
The latest release of SNA-Gate allows an asynchronous printer to participate in an IBM Logical Unit Type 3 with a host application. IBM's Logical Unit Type 3 enables intelligent printers to interpret and execute 3270 buffer commands and orders, typically sent on an LU T2 ses- sion. In this environment, SNA_Gate performs command interpretation and data management for the printer.
The NSP also furnishes downline load and upline dump- ing capabilities for network control information and sta- tus displays. Macros in NSP provide the means to configure SNA-Gate ports for ASCII or BSC operation.
NSP works under the MVS and DOS operating systems.
SNA-Gate interfaces with IBM host database subsystems, including IMS, CICS, TSO, and RJE (JES2, JES3, and POWER). In addition, SNA-Gate responds to commands from IBM's network management products.
SNA-Gate supports a 64K bps, SDLC data link on the host side and 300 to 9600 bps links to data devices on the terminal side. The unit connects to the host through mul- tidrop, dial up, or leased lines. Through an integral modem-sharing facility, SNA-Gate can be daisy-chained so that other SNA devices can share the same line. In this type of application, SNA-Gate appears as a multidropped PU.T2 in the network.
SNA-Gate's SDLC port, which serves as the link to the host, supports the following: an RS-232-C connector; in- ternal or external clocking; synchronous or asynchronous transmission; 110 to 19.2K bps transmission speed; half- or full-duplex operation; and NRZI or non-NRZI coding.
An optional V.35 interface card supports SDLC speeds to 64K bps. Users can configure the SDLC port for any eight-bit SDLC polling address.
A digital splitter on the SDLC port drives the daisychain port, which appears as a multidrop on the SDLC link.
This port has an RS-232-C interface and can take or supply clocking. It has passthrough signals on pins 2 through 8, 15, 17, 20, and 24.
Devices attach to the SNA_Gate through terminal ports that support the RS-232-C interface, internal or external
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C23-659-106 Protocol Conversion Systems
Netlink SNA-Gate
clocking, full EIA pinout, DTE or DCE operation, syn- chronous or asynchronous transmission, full-duplex oper- ation, and 300 to 9600 bps transmission speeds.
The latest release of SNA_Gate supports the five-bit CCITT alphabet No.2, also known as the Baudot Code.
This enhancement enables telex machines to communi- cate over an SNA network through an LU T 1 session.
DEVICE CONTROL
The installation of SNA-Gate resembles the installation of any other SNA-type controller. SNA-Gate must be accurately identified to VT AM, NCP, and host sub- systems, and all devices attached to SNA-Gate must be defined through SNA-Gate configuration macros. To generate an SNA-Gate configuration, users must assem- ble macros defining the characteristics of each SNA-Gate attachment and execute a configuration generator pro- gram to format internal tables for devices attached to the SNA-Gate. The system incorporates supermacros that define the characteristics of commonly used terminals.
Error indications show up on an alphanumeric display, and LEDs monitor system status and line activity. ASCII and BSC port parameters, configured via a host-resident Network Support Program, are downline loaded to SNA- _Gate.
If necessary, a user can extend supermacros and retain configurations and executable code in a host-resident li- brary. ASCII and BSC port parameters, configured via the host-resident Network Support Program, are downloaded to SNA-Gate. (The NSP controls SNA-Gate when it is attached to the network.)
SNA-Gate's operating program includes commands used to communicate with the host and the NSP that resides within it. These commands send a message from the SNA- _Gate to the host, establish a local session between SNA- _Gate and another attached device, establish a session with SNA-Gate's Network Processor Control Point, dis- play SNA-Gate status, send an SNA command, send a message on behalf of another attached device, or end a local session. A user can enter the SNA-Gate commands from any attached device that supports a keyboard.
After power-on or reset, SNA_Gate runs a series of diag- nostics for ROM checksum, RAM nondestructive and destructive tests, an SDLC line test, a timer test, and a test of power supplies. After successful completion of the diag- nostic tests, a bootstrap program logs on to the host- resident NSP and identifies itself by sending a logon from the Network Processor Control Point, which provides net- work services such as loading, dumping, and status.
Logon requests repeat automatically every two minutes until a session is bound with NSP. When a session is bound, the SNA-Gate either dumps or loads its memory.
After the operating program, configuration, and any
patches are loaded into SNA-Gate, NSP is unbound. No further communication occurs between SNA-Gate and NSP until another downline load or upline dump is re- quired or an operator sends a command through NSP to the SNA-Gate Network Processor Control Point.
Users can monitor and control the activity of NSP through a Network Support Console, which can be any configuration-authorized LU Type 1 or Type 2 device located anywhere in the network. While logged on, the console receives messages about NSP activities. To access these messages, users enter a predefined terminal logon sequence and a valid password. After logon through a Network Support Console, an operator can command a printer to log all NSP message traffic. Through a series of NSP commands entered through the console, operators can perform a variety of functions, such as starting or stopping a log of NSP activity, adding an SNA-Gate definition to those defined in the start-up procedure, re- loading the SNA-Gate from the host, and communicating with the Network Processor Control Point about SNA- _Gate control.
To implement emulation, SNA-Gate supports software modules, which include SNA PU.T2, Asynchronous Com- munications, RJE Station Facility, and Bisynchronous Communications. The modules provide the following ba- sic functions:
• SNA PU.T2-provides a modular software structure with well-defined interfaces between layers that conform to the structure of SNA. Discrete layered support in- cludes Data Link Control, Path Control, Transmission Control, Data Flow Control, Network Addressable Unit Services, up to 255 Logical Units, SNA Capabilities, and Communications Network Management.
• Asynchronous Communications-allows asynchronous ASCII devices (TTY compatible) to work as LU Type 0, Type 1, or Type 2 devices in an SNA network. Addi- tional support enables an ASCII device to look like the datastream from an IBM 3767 or 3776 with an exten- sion supporting outbound Function Management Head- ers. This feature allows access to RJE packages, TSO, CICS, and IMS. ASCII devices that operate with SNA- _Gate include keyboard printers, terminals, visual dis- play units (VDUs), microcomputers, minicomputers, output-only devices, letter-quality printers, plotters, and optical character readers. The asynchronous module supports IBM 3767 screens in line-by-line or full-screen emulation of IBM 3278 Models 2, 3, 4, 5, and 3279 four-color devices. This feature allows asynchronous ASCII VDUs to be functionally compatible with IBM 3278 VDUs. The module provides code and configura- tion parameters that take advantage of functions similar to those of an IBM 3278, commonly available on ASCII screens. An ASCII module "swap-on-bind" command allows a user to log on to SNA-Gate as an LU Type 2 device and then switch to an LU Type 1 device and
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C23-659-1 07 Protocol Conversion Systems
Netlink SNA-Gate
reverse the process. Another command authorizes the placement of multiple logical units on a single ASCII port.
• RJE Station Facility-allows SNA-Gate to act as a mul- tiple logical unit (MLU) RJE station. The RJE Station Facility consists of a series of up to eight LUs that can log on to JES2 or JES3 automatically when SNA-Gate is loaded or from any device attached to SNA-Gate. To achieve this capability, the user must define additional LUs-end of sessions that run on the logical line de- fined in JES2 rather than on physical devices in SNA- _Gate. LU Type 1 devices that establish local sessions with the RJE Station Facility identify themselves as readers, printers, punches, exchange disks, or consoles.
• Bisynchronous Communications-maps BSC protocols to SNA. This capability allows IBM 2770, 2780, 3780, 3741, polled 3780 or 3270 devices, as well as RJE and data-entry terminals, minicomputers, microcomputers, or mainframes using the BSC protocol, to access a host operating under SNA. The mapping performed for BSC preserves the end-to-end nature of SNA.
As an option, users can equip SNA-Gate with a Bur- roughs Poll Select Emulator module so that Burroughs TD
830 terminals can emulate LU Type 2 devices with limi- tations and TC 4000 printers can emulate LU Type 1 units. This module also offers the following capabilities:
upstream passthrough for Burroughs terminals to a Bur- roughs 6700, 6800 CPU; the ability to log on to either an IBM or Burroughs host and switch between the two on a session basis; support, through configuration macros, for configuring Burroughs terminals; and LU Type 0 emula- tion.
PHYSICAL SPECIFICATIONS
SNA-Gate is 7.08 inches high, 17.44 inches wide, 19.125 inches deep, and weighs approximately 30 pounds. Power requirements are as follows: 120 V AC or 240 V AC; 140 W; and 50 to 60 Hz.
PRICING
The async/bisync 3703-1 ranges in price from $6,000 to
$9,500; the 3703-1A, asynchronous-only model ranges from $4,000 to $8,000; and the 3703-1B, bisynchronous- only model costs between $4,500 and $6,000. Netlink offers quantity discounts. D
MAY 1989 COPYRIGHT © 1989 McGRAW-HILL, INCORPORATED. REPRODUCTION PROHIBITED DA T APRO RESEARCH, DELRAN NJ 08075 USA
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C23-659-101 Protocol Conversion Systems
Netlink SNA_Gate
MANAGEMENT SUMMARY
The SNA-Gate is Netlink's answer to environments in which bisynchronous and asynchronous devices exist with- in an SNA network. Although called a gate, the unit is not a gateway between networks. Rather, the SNA-Gate is actu- ally an IBM Physical Unit Type 2 (PU.T2) cluster control- ler and multifunction protocol converter in one device.
The unit connects non-SNA devices to SNA networks. The specific devices supported include bisync 3270 and 3780/
2780 devices, bisync hosts and minicomputers, and all asynchronous devices. The product has its own Intel 8086 microprocessor and memory, and functions as a software- based system, allowing for the accommodation of a num- ber of different protocols in the SNA network.
The device is basically an upgraded version of Netlink's 3703 Network Processor. While the 3703 had 12 ports, the SNA-Gate supports 16 non-SNA lines over an SNA/
SDLe host link. The 3703 could handle 9600 bps up- stream, but the SNA-Gate is able to handle up to 64K bps.
The memory of the new product has been greatly expanded to either 512K or 704K bytes, whereas the 3703 Network Processor had a 384K-byte memory capacity. The 3703 also was available in two models only: one supported both bisynchronous- and asynchronous-to-SNA conversions, and the other supported asynchronous-to-SNA conver- sions only. Netlink has taken the SNA-Gate one step further, by creating a third version that supports bisynchro- nous-only conversion. Netlink has also made the price of the SNA-Gate more attractive than its predecessor's cost.
The 3703 async/bisync version began at $8,700 for four ports, while the newer model costs $2,700 less.
The SNA-Gate supports direct, leased, multidrop, and dial-up lines. The unit eliminates separate communica- tions lines and host front-end ports for non-SNA devices. It also eliminates host/front-end processor support facilities like EP and NTO for non-SNA devices. The major attrac- tion of this product is that it can be softloaded and centrally managed. At this time, no other product on the market has this capability. Because the SNA-Gate is softloaded, a user
t>
The Netlink. Inc. SNJLGate is more than just a protocol converter. The product can function as a cluster controller. a line con- centrator. and a remote job entry station facility. The unit provides multiple protocol conversions. including concurrent asynchro- nous and bisynchronous to Systems Net- work Architecture (SNA). The SNJLGate emulates an IBM Physical Unit Type 2 clus- ter controller. providing a gateway to the IBM SNA/SDLC environment.
MODELS: 3703-1 (multifunction SNJL- Gate); 3703-1 A (asynchronous-only ver- sion); and 3703-1 B (bisynchronous-only model).
CONVERSION: ASCII to SNA; BSC 3270.
37BO/2780. and other bisync devices to SNA; and RJE to SNA.
TRANSMISSION RATES: 64K bps on host link; 300 to 9600 bps on terminal links.
COMPETITION: IBM 3708. 3710. and 3274 51 C control unit.
PRICE: 3703-1 ranges from $6.000 to
$9.500; 3703-1A ranges from $4.000 to
$6.000; and 3703-1 B ranges from $4.500 to $6.000. Quantity discounts are available.
CHARACTERISTICS
VENDOR: Netlink, Inc., 3214 Spring Forest Road, Ra- leigh, North Carolina 27604. Telephone (919) 878-8612.
DATE OF FIRST ANNOUNCEMENT: 1986.
DATE OF FIRST DELIVERY: 1986.
NUMBER INSTALLED TO DATE: Over 1,000.
SERVICED BY: Netlink, Inc.
Netlink's SNA_Gate allows asyn- chronous and bisynchronous de- vices to access Systems Network Architecture (SNA).
JUNE 1987 © 1987 DATAPRO RESEARCH CORPORATION. DELRAN. NJ 08075 USA REPRODUCTION PROHIBITED-FOR REPRINTS. CALL 1-800-328-2776
